Tobacco smoke filter

ABSTRACT

A filter for tobacco smoke which is capable of removing nicotine and other constituents from the smoke is disclosed. The filter element is composed at least in part of cellulose sulfate compound of the formula R-cellulose-OSO3X wherein R is one or more functional groups selected from the group consisting of methyl, ethyl, propyl, butyl, hydroxyethyl, hydroxylpropoxyl and hydroxylbutoxyl, and X is selected from the group consisting of hydrogen, sodium and potassium. The preferred compound is sodium ethylcellulose sulfate.

United States Patent Tune [ 51 May 9,1972

[54] TOBACCO SMOKE FILTER [72] Inventor: Deger Tunc, Edison, NJ.

[73] Assignee: Johnson & Johnson [22] Filed: Jan. 28, 1970 [21] Appl.No.: 6,644

OTHER PUBLICATIONS Slowig, W. D. and M. E. Rowley Sodium Ethylcellulose Sulfate Textile Research Journal 38: 879- 884 1968 (September) Primary Examiner-Samuel Koren Assistant E.\'aminerG. M. Yahwak Attorney-Michael Q. Tatlow, Harold L. Warner and Robert L. Minier [57 ABSTRACT A filter for tobacco smoke which is capable of removing nicotine and other constituents from the smoke is disclosed. The filter element is composed at least in part of cellulose sulfate compound of the formula R-cellulose-OSO X wherein R is one or more functionalgroups selected from the group consisting of methyl, ethyl, propyl, butyl, hydroxyethyl, hydroxylpropoxyl and hydroxylbutoxyl, and X is selected from the group consisting of hydrogen, sodium and potassium. The preferred compound is sodium ethylcellulose sulfate.

2 Claims, No Drawings TOBACCO SMOKE FILTER The harmful physiological effects of volatile constituents contained in tobacco smoke has long been recognized. it is well known that tobacco smoke contains various alkaloids and health-affecting volatile materials such as nicotine as well as tar and other constituents which tend to physiologically irritate the smoker. Various efforts have been made to remove nicotine from tobacco before it is burned, or remove nicotine and other harmful constituents from the smoke as the tobacco is burned. However, denicotined tobacco is generally considered by smokers to be inferior in taste to untreated tobacco. Numerous filters on tips of cigarettes as well as filters for pipes and cigarette holders have also been used in an attempt to filter the undesirable constituents from the tobacco smoke.

I have discovered that relatively small amounts of a cellulose sulfate compound can be added to the standard filter elements used in filter tip cigarettes or to the filter elements in pipes and cigarette holders which will remove materially increased amounts of nicotine from the tobacco smoke. The cellulose sulfate compounds useful in the present may be represented generally by the formula R cellulose-OSO -,X wherein R may be one or more functional groups selected from the group consisting of methyl, ethyl, propyl, butyl, hydroxyethyl, hydroxypropoxyl and hydroxybutoxyl, and X is selected from the group consisting of hydrogen, sodium and potassium. The alkali metal ethylcellulose sulfates are the preferred compounds in the practice of the present invention. The particular alkali metal ethylcellulose sulfate which I have found to be particularly effective is sodium ethylcellulose sulfate. The sodium ethylcellulose sulfate has the following formula:

CHzCHa Cellulose 0 CHQCHS OS O2-ONa This material can be formed by sulfating ethylcellulose with sodium acetyl sulfate that has been previously prepared in an acetic acid solution from acetic anhydride, sulfuric acid and sodium sulfate. The sodium acetyl sulfate is reactive with ethylcellulose to form the sodium ethylcellulose sulfate. The preparation of this product is fully described in the Textile Research Journal, Volume 38, Number 9, September 1968, pages 879-884. The other cellulose sulfate compounds described previously can be prepared using the procedure described above but employing as a starting material a cellulose derivativewith the desired functional group R, and an acid or salt to yield the desired group X.

The cellulose sulfate compound may be employed as an additive to the filter material of the presently used tobacco filter media or employed in powder or granular form as the main component in the filter. When employed as an additive, the material of the present invention may be ground into a fine powder of from 80 to 100 mesh and applied to a filter medium mass, such as cellulose acetate fibers, cotton or tissue paper. The cellulose sulfate compound may also be dissolved in water and applied as a solution to the filter medium. The cellulose sulfate compound is added to water to form a solution containing from 5 to percent of the cellulose sulfate compound. The solution may then be sprayed, impregnated or otherwise applied to the filter media, and the filter media dried to deposit the solid cellulose sulfate compound.

When the cellulose sulfate compound is employed as the major component in the filter mass, it is employed in the form of a powder. The powder may be packed in a cylindrical container with partially opened ends for use in a cigarette holder or in a pipe. The powder may also be packed in a cylindrical paper tube with fibrous or paper packing at each end and attached to a cigarette as a filter element.

In addition to the utilization of the cellulose sulfate compound as an additive with cellulose acetate fibers and tissue paper filters commonly used in filtering tobacco smoke, the material may also be employed with wood pulp fibers to form the filter. Woodpulp board may be impregnated with a solution of the cellulose sulfate compound in water. The board is then dried to remove excess moisture and then disentigrated in the normal manner to form wood pulp fibers. The impregnated wood pulp fibers are then formed in standard filter elements and attached to cigarettes.

The amount of cellulose sulfate compound added to the standard filter medium may be as low as 5 percent'based on the total weight of the filter element.

In the following examples the cigarettes having attached thereto the indicated filters were smoked through a smoking apparatus designed so that a 35 cubic centimeter puff was taken every minute for 7 minutes. The total amount of smoke passing through the filters was 280 cubic centimeters. The smoke passing through the filter was then passed through a condenser imbedded in dry ice and through three flasks containing 5 mililiters of toluene as a solvent. These wash solutions were combined and used to dissolve the material condensed in the condenser.

EXAMPLE I A commercially available cellulose acetate cigarette filter and a filter element containing 0.3 grams of sodium ethylcellulose sulfate between two glass wool plugs in a plastic tube 'were attached to cigarettes and smoked in the device previously described. The condensates were analyzed by ultraviolet spectroscopy and both samples had an absorption peak of 285 milimicrons, but the peak heights were different. The relative amounts of the condensates were as follows:

TABLE I Filter Absorption Cellulose Acetate 1.36 SECS 0.55

sodium ethylcellulose sulfate This table shows that the SECS filter was more efficient in removing the condensed material from the smoke than the cellulose acetate filter.

EXAMPLE I] The cellulose acetate and SECS filter media employed in Example] were stirred in ml. of water and analyzed by ultraviolet spectroscopy for nicotine which has an absorption peak at 259 milimicrons. The results are shown in Table II.

TABLE ll Filter Absorption at 259 mp.

Cellulose Acetate 0.240 SECS 0.530

This data shows that the SECS filter is more effective in removing nicotine than the cellulose acetate filters.

EXAMPLE "I Four cigarettes with various filters were smoked on the smoking apparatus previously described. The filters-were analyzed for nicotine in same manner described in Example ll."

Filter Absorption at 259 mp.

Cellulose Acetate 0.545 Charcoal Filter 0.565 SECS Powder 0.955 SECS-Pulp 0.860

EXAMPLE IV The four filters of the type employed in Example lll were used on cigarettes on the previously described smoking device. The wash solutions and the material in the condenser were combined and analyzed for nicotine using a gas chromatograph to determine the relative amounts of nicotine passing through the filters. Using the cellulose acetate filter as a base and assigning it a value of 100 in effectiveness in removing nicotine, the results are as follows:

TABLE IV Filter Removal of Nicotine Cellulose Acetate Charcoal Filter 2l7 SECS Powder 279 SECS-Pulp 376 

2. A tobacco smoke filter as in Claim 1 positioned in a smoke passage of a tobacco smoking article. 